1
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Kohn EM, Konovalov K, Gomez CA, Hoover GN, Yik AKH, Huang X, Martell JD. Terminal Alkyne-Modified DNA Aptamers with Enhanced Protein Binding Affinities. ACS Chem Biol 2023; 18:1976-1984. [PMID: 37531184 DOI: 10.1021/acschembio.3c00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Nucleic acid-based receptors, known as aptamers, are relatively fast to discover and manufacture but lack the diverse functional groups of protein receptors (e.g., antibodies). The binding properties of DNA aptamers can be enhanced by attaching abiotic functional groups; for example, aromatic groups such as naphthalene slow dissociation from proteins. Although the terminal alkyne is a π-electron-rich functional group that has been used in small molecule drugs to enhance binding to proteins through noncovalent interactions, it remains unexplored for enhancing DNA aptamer binding affinity. Here, we demonstrate the utility of the terminal alkyne for improving the binding of DNA to proteins. We prepared a library of 256 terminal-alkyne-bearing variants of HD22, a DNA aptamer that binds the protein thrombin with nanomolar affinity. After a one-step thrombin-binding selection, a high-affinity aptamer containing two alkynes was discovered, exhibiting 3.2-fold tighter thrombin binding than the corresponding unmodified sequence. The tighter binding was attributable to a slower rate of dissociation from thrombin (5.2-fold slower than HD22). Molecular dynamics simulations with enhanced sampling by Replica Exchange with Solute Tempering (REST2) suggest that the π-electron-rich alkyne interacts with an asparagine side chain N-H group on thrombin, forming a noncovalent interaction that stabilizes the aptamer-protein interface. Overall, this work represents the first case of terminal alkynes enhancing the binding properties of an aptamer and underscores the utility of the terminal alkyne as an atom economical π-electron-rich functional group to enhance binding affinity with minimal steric perturbation.
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Affiliation(s)
- Eric M Kohn
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kirill Konovalov
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Christian A Gomez
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Gillian N Hoover
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Andrew Kai-Hei Yik
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Xuhui Huang
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Jeffrey D Martell
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705, United States
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2
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Hu Z, Li Y, Figueroa-Miranda G, Musal S, Li H, Martínez-Roque MA, Hu Q, Feng L, Mayer D, Offenhäusser A. Aptamer based biosensor platforms for neurotransmitters analysis. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.117021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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3
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Sanford AA, Manuel BA, Romero-Reyes MA, Heemstra JM. Combating small molecule environmental contaminants: detection and sequestration using functional nucleic acids. Chem Sci 2022; 13:7670-7684. [PMID: 35865900 PMCID: PMC9258336 DOI: 10.1039/d2sc00117a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/26/2022] [Indexed: 12/05/2022] Open
Abstract
Small molecule contaminants pose a significant threat to the environment and human health. While regulations are in place for allowed limits in many countries, detection and remediation of contaminants in more resource-limited settings and everyday environmental sources remains a challenge. Functional nucleic acids, including aptamers and DNA enzymes, have emerged as powerful options for addressing this challenge due to their ability to non-covalently interact with small molecule targets. The goal of this perspective is to outline recent efforts toward the selection of aptamers for small molecules and describe their subsequent implementation for environmental applications. Finally, we provide an outlook that addresses barriers that hinder these technologies from being widely adopted in field friendly settings and propose a path forward toward addressing these challenges.
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Affiliation(s)
- Aimee A Sanford
- Department of Chemistry, Emory University Atlanta Georgia 30322 USA
| | - Brea A Manuel
- Department of Chemistry, Emory University Atlanta Georgia 30322 USA
| | - Misael A Romero-Reyes
- Department of Chemistry, Emory University Atlanta Georgia 30322 USA
- Department of Chemistry, Hanover College Hanover Indiana 47243 USA
| | - Jennifer M Heemstra
- Department of Chemistry, Emory University Atlanta Georgia 30322 USA
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta GA 30332 USA
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4
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A system for multiplexed selection of aptamers with exquisite specificity without counterselection. Proc Natl Acad Sci U S A 2022; 119:e2119945119. [PMID: 35290115 PMCID: PMC8944265 DOI: 10.1073/pnas.2119945119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Aptamers have the capacity to discriminate between structurally similar small molecules. However, generating such highly specific aptamers has proven challenging using conventional processes based on counterselection against nontarget molecules. In this work, we describe a high-throughput screening platform that can characterize the specificity of millions of aptamers toward a group of structurally related molecules in a single experiment and generate exquisitely specific aptamers without any counterselection. As exemplars, we generated aptamers with high affinity and specificity toward three structurally related kynurenine metabolites using our platform. Our platform can be readily adapted to other small-molecule targets and should therefore accelerate the development of aptamer reagents with exquisite specificity. Aptamers have proven to be valuable tools for the detection of small molecules due to their remarkable ability to specifically discriminate between structurally similar molecules. Most aptamer selection efforts have relied on counterselection to eliminate aptamers that exhibit unwanted cross-reactivity to interferents or structurally similar relatives to the target of interest. However, because the affinity and specificity characteristics of an aptamer library are fundamentally unknowable a priori, it is not possible to determine the optimal counterselection parameters. As a result, counterselection experiments require trial-and-error approaches that are inherently inefficient and may not result in aptamers with the best combination of affinity and specificity. In this work, we describe a high-throughput screening process for generating high-specificity aptamers to multiple targets in parallel while also eliminating the need for counterselection. We employ a platform based on a modified benchtop sequencer to conduct a massively parallel aptamer screening process that enables the selection of highly specific aptamers against multiple structurally similar molecules in a single experiment, without any counterselection. As a demonstration, we have selected aptamers with high affinity and exquisite specificity for three structurally similar kynurenine metabolites that differ by a single hydroxyl group in a single selection experiment. This process can easily be adapted to other small-molecule analytes and should greatly accelerate the development of aptamer reagents that achieve exquisite specificity for their target analytes.
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5
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Qian S, Chang D, He S, Li Y. Aptamers from random sequence space: Accomplishments, gaps and future considerations. Anal Chim Acta 2022; 1196:339511. [DOI: 10.1016/j.aca.2022.339511] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/12/2022] [Accepted: 01/15/2022] [Indexed: 02/07/2023]
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6
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Yu H, Alkhamis O, Canoura J, Liu Y, Xiao Y. Advances and Challenges in Small‐Molecule DNA Aptamer Isolation, Characterization, and Sensor Development. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202008663] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Haixiang Yu
- Department of Chemistry and Biochemistry Florida International University 11200 SW 8th Street Miami FL 33199 USA
| | - Obtin Alkhamis
- Department of Chemistry and Biochemistry Florida International University 11200 SW 8th Street Miami FL 33199 USA
| | - Juan Canoura
- Department of Chemistry and Biochemistry Florida International University 11200 SW 8th Street Miami FL 33199 USA
| | - Yingzhu Liu
- Department of Chemistry and Biochemistry Florida International University 11200 SW 8th Street Miami FL 33199 USA
| | - Yi Xiao
- Department of Chemistry and Biochemistry Florida International University 11200 SW 8th Street Miami FL 33199 USA
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7
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Yu H, Alkhamis O, Canoura J, Liu Y, Xiao Y. Advances and Challenges in Small-Molecule DNA Aptamer Isolation, Characterization, and Sensor Development. Angew Chem Int Ed Engl 2021; 60:16800-16823. [PMID: 33559947 PMCID: PMC8292151 DOI: 10.1002/anie.202008663] [Citation(s) in RCA: 156] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/16/2021] [Indexed: 12/12/2022]
Abstract
Aptamers are short oligonucleotides isolated in vitro from randomized libraries that can bind to specific molecules with high affinity, and offer a number of advantages relative to antibodies as biorecognition elements in biosensors. However, it remains difficult and labor-intensive to develop aptamer-based sensors for small-molecule detection. Here, we review the challenges and advances in the isolation and characterization of small-molecule-binding DNA aptamers and their use in sensors. First, we discuss in vitro methodologies for the isolation of aptamers, and provide guidance on selecting the appropriate strategy for generating aptamers with optimal binding properties for a given application. We next examine techniques for characterizing aptamer-target binding and structure. Afterwards, we discuss various small-molecule sensing platforms based on original or engineered aptamers, and their detection applications. Finally, we conclude with a general workflow to develop aptamer-based small-molecule sensors for real-world applications.
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Affiliation(s)
- Haixiang Yu
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL, 33199, USA
| | - Obtin Alkhamis
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL, 33199, USA
| | - Juan Canoura
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL, 33199, USA
| | - Yingzhu Liu
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL, 33199, USA
| | - Yi Xiao
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL, 33199, USA
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8
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Kim SW, Yumoto A, Minagawa N, Son K, Heo Y, Ito Y, Uzawa T. Selection of Ovalbumin-specific Binding Peptides through Instant Translation in Ribosome Display Using E. coli Extract. ANAL SCI 2021; 37:707-712. [PMID: 33487600 DOI: 10.2116/analsci.20scp20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In vitro selection has been widely used to generate molecular-recognition elements in analytical sciences. Although reconstituted types of in vitro transcription and translation (IVTT) system, such as PURE system, are nowadays widely used for ribosome display and mRNA/cDNA display, use of E. coli extract is often avoided, presumably because it contains unfavorable contaminants, such as ribonuclease. Nevertheless, the initial speed of protein translation in E. coli extract is markedly faster than that of PURE system. We thus hypothesized that E. coli extract is more appropriate for instant translation in ribosome display than PURE system. Here, we first revisit the potency of E. coli extract for ribosome display by shortening the translation time, and then applied the optimized condition for selecting peptide aptamers for ovalbumin (OVA). The OVA-binding peptides selected using E. coli extract exhibited specific binding to OVA, even in the presence of 50% serum. We conclude that instant translation in ribosome display using E. coli extract has the potential to generate easy-to-use and economical molecular-recognition elements in analytical sciences.
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Affiliation(s)
- Shin-Woong Kim
- Department of Biological Sciences, Tokyo Metropolitan University.,Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research
| | - Akiko Yumoto
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science
| | - Noriko Minagawa
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science
| | - Kon Son
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science
| | - Yun Heo
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science
| | - Yoshihiro Ito
- Department of Biological Sciences, Tokyo Metropolitan University.,Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research.,Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science
| | - Takanori Uzawa
- Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research.,Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science
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9
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Mastronardi E, Cyr K, Monreal CM, DeRosa MC. Selection of DNA Aptamers for Root Exudate l-Serine Using Multiple Selection Strategies. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4294-4306. [PMID: 33600189 DOI: 10.1021/acs.jafc.0c06796] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Agricultural biosensing can aid decisions about crop health and maintenance, because crops release root exudates that can inform about their status. l-Serine has been found to be indicative of nitrogen uptake in wheat and canola. The development of a biosensor for l-serine could allow farmers to monitor crop nutrient demands more precisely. The development of robust l-serine-binding DNA aptamers is described. Because small molecules can be challenging targets for Systematic Evolution of Ligands by EXponential enrichment (SELEX), three separate DNA libraries were used for SELEX experiments. A l-homocysteine aptamer was randomized to create a starting library for a l-serine selection (randomized SELEX). The final selection rounds of the l-homocysteine selection were also used as a starting library for l-serine (redirected SELEX). Finally, an original DNA library was used (original SELEX). All three SELEX experiments produced l-serine-binding aptamers with micromolar affinity, with Red.1 aptamer having a Kd of 7.9 ± 3.6 μM. Truncation improved the binding affinity to 5.2 ± 2.7 μM, and from this sequence, a Spiegelmer with improved nuclease resistance was created with a Kd of 2.0 ± 0.8 μM. This l-serine-binding Spiegelmer has the affinity and stability to be incorporated into aptamer-based biosensors for agricultural applications.
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Affiliation(s)
- Emily Mastronardi
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Kathryn Cyr
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Carlos M Monreal
- Agriculture and Agri-Food Canada, K.W. Neatby Building, Ottawa, Ontario K1A 0C6, Canada
| | - Maria C DeRosa
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
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10
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Yu H, Luo Y, Alkhamis O, Canoura J, Yu B, Xiao Y. Isolation of Natural DNA Aptamers for Challenging Small-Molecule Targets, Cannabinoids. Anal Chem 2021; 93:3172-3180. [PMID: 33528997 DOI: 10.1021/acs.analchem.0c04592] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Aptamers are nucleic acid-based affinity reagents that are isolated via an in vitro process known as systematic evolution of ligands by exponential enrichment (SELEX). Despite their great potential for a wide range of analytical applications, there are relatively few high-quality small-molecule binding aptamers, especially for "challenging" targets that have low water solubility and/or limited moieties for aptamer recognition. The use of libraries containing chemically modified bases may improve the outcome of some SELEX experiments, but this approach is costly and yields inconsistent results. Here, we demonstrate that a thoughtfully designed SELEX procedure with natural DNA libraries can isolate aptamers with high affinity and specificity for challenging small molecules, including targets for which such selections have previously failed. We first isolate a DNA aptamer with nanomolar affinity and high specificity for (-)-trans-Δ9-tetrahydrocannabinol (THC), a target previously thought to be unsuitable for SELEX with natural DNA libraries. We subsequently isolate aptamers that exhibit high affinity and cross-reactivity to two other challenging targets, synthetic cannabinoids UR-144 and XLR-11, while maintaining excellent specificity against a wide range of non-target interferents. Our findings demonstrate that natural nucleic acid libraries can yield high-quality aptamers for small-molecule targets, and we outline a robust workflow for isolating other such aptamers in future selection efforts.
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Affiliation(s)
- Haixiang Yu
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida, 33199, United States
| | - Yingping Luo
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida, 33199, United States.,State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of TCM Evaluation and Translational Research, Department of Complex Prescription of TCM, China Pharmaceutical University, Nanjing 211198, P. R. China
| | - Obtin Alkhamis
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida, 33199, United States
| | - Juan Canoura
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida, 33199, United States
| | - Boyang Yu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of TCM Evaluation and Translational Research, Department of Complex Prescription of TCM, China Pharmaceutical University, Nanjing 211198, P. R. China
| | - Yi Xiao
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida, 33199, United States
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11
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Azobenzene-modified DNA aptamers evolved by capillary electrophoresis (CE)-SELEX method. Bioorg Med Chem Lett 2020; 31:127607. [PMID: 33039563 DOI: 10.1016/j.bmcl.2020.127607] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/29/2020] [Accepted: 10/03/2020] [Indexed: 12/20/2022]
Abstract
Chemically modified aptamers have recently emerged as important materials for nucleic acid based therapeutics and diagnostic tools. Here, we report in vitro evolution of azobenzene-modified DNA aptamers by capillary electrophoresis (CE)-SELEX method. Azobenzene has been considered to be a fascinating functional group due to its trans-cis photo-isomerization property. We harnessed C5-azobenzene-modified 2'-deoxyuridine (dUAz) as a azobenzene-tethered unit and subjected it to CE-SELEX with human thrombin. The obtained dUAz-modified aptamer showed strong binding affinity toward human thrombin and could be reversibly photo-isomerized by different wavelengths of light. This work demonstrates that CE-SELEX is a powerful method to obtain chemically modified aptamers and dUAz is an excellent photo-responsive nucleoside for nucleic acid photo-switches.
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12
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Dey S, Sczepanski JT. In vitro selection of l-DNA aptamers that bind a structured d-RNA molecule. Nucleic Acids Res 2020; 48:1669-1680. [PMID: 31950158 PMCID: PMC7038948 DOI: 10.1093/nar/gkz1236] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/25/2019] [Accepted: 01/03/2020] [Indexed: 12/22/2022] Open
Abstract
The development of structure-specific RNA binding reagents remains a central challenge in RNA biochemistry and drug discovery. Previously, we showed in vitro selection techniques could be used to evolve l-RNA aptamers that bind tightly to structured d-RNAs. However, whether similar RNA-binding properties can be achieved using aptamers composed of l-DNA, which has several practical advantages compared to l-RNA, remains unknown. Here, we report the discovery and characterization of the first l-DNA aptamers against a structured RNA molecule, precursor microRNA-155, thereby establishing the capacity of DNA and RNA molecules of the opposite handedness to form tight and specific ‘cross-chiral’ interactions with each other. l-DNA aptamers bind pre-miR-155 with low nanomolar affinity and high selectivity despite the inability of l-DNA to interact with native d-RNA via Watson–Crick base pairing. Furthermore, l-DNA aptamers inhibit Dicer-mediated processing of pre-miRNA-155. The sequence and structure of l-DNA aptamers are distinct from previously reported l-RNA aptamers against pre-miR-155, indicating that l-DNA and l-RNA interact with the same RNA sequence through unique modes of recognition. Overall, this work demonstrates that l-DNA may be pursued as an alternative to l-RNA for the generation of RNA-binding aptamers, providing a robust and practical approach for targeting structured RNAs.
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Affiliation(s)
- Sougata Dey
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA
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13
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Kong D, Movahedi M, Mahdavi-Amiri Y, Yeung W, Tiburcio T, Chen D, Hili R. Evolutionary Outcomes of Diversely Functionalized Aptamers Isolated from in Vitro Evolution. ACS Synth Biol 2020; 9:43-52. [PMID: 31774997 DOI: 10.1021/acssynbio.9b00222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Expanding the chemical diversity of aptamers remains an important thrust in the field in order to increase their functional potential. Previously, our group developed LOOPER, which enables the incorporation of up to 16 unique modifications throughout a ssDNA sequence, and applied it to the in vitro evolution of thrombin binders. As LOOPER-derived highly modified nucleic acids polymers are governed by two interrelated evolutionary variables, namely, functional modifications and sequence, the evolution of this polymer contrasts with that of canonical DNA. Herein we provide in-depth analysis of the evolution, including structure-activity relationships, mapping of evolutionary pressures on the library, and analysis of plausible evolutionary pathways that resulted in the first LOOPER-derived aptamer, TBL1. A detailed picture of how TBL1 interacts with thrombin and how it may mimic known peptide binders of thrombin is also proposed. Structural modeling and folding studies afford insights into how the aptamer displays critical modifications and also how modifications enhance the structural stability of the aptamer. A discussion of benefits and potential limitations of LOOPER during in vitro evolution is provided, which will serve to guide future evolutions of this highly modified class of aptamers.
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Affiliation(s)
- Dehui Kong
- Department of Chemistry, University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| | - Matina Movahedi
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Yasaman Mahdavi-Amiri
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Wayland Yeung
- Department of Chemistry, University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| | - Tristan Tiburcio
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Dickson Chen
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Ryan Hili
- Department of Chemistry, University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
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14
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Odeh F, Nsairat H, Alshaer W, Ismail MA, Esawi E, Qaqish B, Bawab AA, Ismail SI. Aptamers Chemistry: Chemical Modifications and Conjugation Strategies. Molecules 2019; 25:E3. [PMID: 31861277 PMCID: PMC6982925 DOI: 10.3390/molecules25010003] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/14/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Soon after they were first described in 1990, aptamers were largely recognized as a new class of biological ligands that can rival antibodies in various analytical, diagnostic, and therapeutic applications. Aptamers are short single-stranded RNA or DNA oligonucleotides capable of folding into complex 3D structures, enabling them to bind to a large variety of targets ranging from small ions to an entire organism. Their high binding specificity and affinity make them comparable to antibodies, but they are superior regarding a longer shelf life, simple production and chemical modification, in addition to low toxicity and immunogenicity. In the past three decades, aptamers have been used in a plethora of therapeutics and drug delivery systems that involve innovative delivery mechanisms and carrying various types of drug cargos. However, the successful translation of aptamer research from bench to bedside has been challenged by several limitations that slow down the realization of promising aptamer applications as therapeutics at the clinical level. The main limitations include the susceptibility to degradation by nucleases, fast renal clearance, low thermal stability, and the limited functional group diversity. The solution to overcome such limitations lies in the chemistry of aptamers. The current review will focus on the recent arts of aptamer chemistry that have been evolved to refine the pharmacological properties of aptamers. Moreover, this review will analyze the advantages and disadvantages of such chemical modifications and how they impact the pharmacological properties of aptamers. Finally, this review will summarize the conjugation strategies of aptamers to nanocarriers for developing targeted drug delivery systems.
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Affiliation(s)
- Fadwa Odeh
- Faculty of Science, The University of Jordan, Amman 11942, Jordan; (F.O.); (H.N.); (A.A.B.)
- Hamdi Mango Center for Scientific Research, The University of Jordan, Amman 11942, Jordan
| | - Hamdi Nsairat
- Faculty of Science, The University of Jordan, Amman 11942, Jordan; (F.O.); (H.N.); (A.A.B.)
| | - Walhan Alshaer
- Cell Therapy Center, The University of Jordan, Amman 11942, Jordan
| | - Mohammad A. Ismail
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
| | - Ezaldeen Esawi
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
| | - Baraa Qaqish
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
| | - Abeer Al Bawab
- Faculty of Science, The University of Jordan, Amman 11942, Jordan; (F.O.); (H.N.); (A.A.B.)
- Hamdi Mango Center for Scientific Research, The University of Jordan, Amman 11942, Jordan
| | - Said I. Ismail
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
- Qatar Genome Project, Qatar Foundation, Doha 5825, Qatar
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15
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Verdonck L, Buyst D, de Vries AM, Gheerardijn V, Madder A, Martins JC. Tethered imidazole mediated duplex stabilization and its potential for aptamer stabilization. Nucleic Acids Res 2019; 46:11671-11686. [PMID: 30418582 PMCID: PMC6294506 DOI: 10.1093/nar/gky1062] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/01/2018] [Indexed: 12/15/2022] Open
Abstract
Previous investigations of the impact of an imidazole-tethered thymidine in synthetic DNA duplexes, monitored using UV and NMR spectroscopy, revealed a base context dependent increase in thermal stability of these duplexes and a striking correlation with the imidazolium pKa. Unrestrained molecular dynamics (MD) simulations demonstrated the existence of a hydrogen bond between the imidazolium and the Hoogsteen side of a nearby guanosine which, together with electrostatic interactions, form the basis of the so-called pKa-motif responsible for these duplex-stabilizing and pKa-modulating properties. Here, the robustness and utility of this pKa-motif was explored by introducing multiple imidazole-tethered thymidines at different positions on the same dsDNA duplex. For all constructs, sequence based expectations as to pKa-motif formation were supported by MD simulations and experimentally validated using NOESY. Based on the analysis of the pKa values and melting temperatures, guidelines are formulated to assist in the rational design of oligonucleotides modified with imidazolium-tethered thymidines for increased thermal stability that should be generally applicable, as demonstrated through a triply modified construct. In addition, a proof-of-principle study demonstrating enhanced stability of the l-argininamide binding aptamer modified with an imidazole-tethered thymidine in the presence and absence of ligand, demonstrates its potential for the design of more stable aptamers.
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Affiliation(s)
- Lars Verdonck
- Department of Organic and Macromolecular Chemistry, Organic and Biomimetic Chemistry Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium.,Department of Organic and Macromolecular Chemistry, NMR and Structure Analysis Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium
| | - Dieter Buyst
- Department of Organic and Macromolecular Chemistry, NMR and Structure Analysis Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium.,NMR Expertise Centre, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium
| | - Anne-Mare de Vries
- Department of Organic and Macromolecular Chemistry, Organic and Biomimetic Chemistry Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium.,Department of Organic and Macromolecular Chemistry, NMR and Structure Analysis Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium
| | - Vicky Gheerardijn
- Department of Organic and Macromolecular Chemistry, Organic and Biomimetic Chemistry Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium
| | - Annemieke Madder
- Department of Organic and Macromolecular Chemistry, Organic and Biomimetic Chemistry Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium
| | - José C Martins
- Department of Organic and Macromolecular Chemistry, NMR and Structure Analysis Research Group, Ghent University, Gent, Oost-Vlaanderen 9000, Belgium
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Mastronardi E, Monreal C, DeRosa MC. Personalized Medicine for Crops? Opportunities for the Application of Molecular Recognition in Agriculture. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:6457-6461. [PMID: 28985063 DOI: 10.1021/acs.jafc.7b03295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This perspective examines the detection of rhizosphere biomarkers, namely, root exudates and microbial metabolites, using molecular recognition elements, such as molecularly imprinted polymers, antibodies, and aptamers. Tracking these compounds in the rhizosphere could provide valuable insight into the status of the crop and soil in a highly localized way. The outlook and potential impact of the combination of molecular recognition and other innovations, such as nanotechnology and precision agriculture, and the comparison to advances in personalized medicine are considered.
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Affiliation(s)
- Emily Mastronardi
- Department of Chemistry , Carleton University , 1125 Colonel By Drive , Ottawa , Ontario K1S 5B6 , Canada
| | - Carlos Monreal
- Agriculture and Agrifood Canada , 960 Carling Avenue , Neatby Building, Ottawa , Ontario K1Y 4X2 , Canada
| | - Maria C DeRosa
- Department of Chemistry , Carleton University , 1125 Colonel By Drive , Ottawa , Ontario K1S 5B6 , Canada
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17
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MacPherson IS, Temme JS, Krauss IJ. DNA display of folded RNA libraries enabling RNA-SELEX without reverse transcription. Chem Commun (Camb) 2018; 53:2878-2881. [PMID: 28220154 DOI: 10.1039/c6cc09991b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A method for the physical attachment of folded RNA libraries to their encoding DNA is presented as a way to circumvent the reverse transcription step during systematic evolution of RNA ligands by exponential enrichment (RNA-SELEX). A DNA library is modified with one isodC base to stall T7 polymerase and a 5' "capture strand" which anneals to the nascent RNA transcript. This method is validated in a selection of RNA aptamers against human α-thrombin with dissociation constants in the low nanomolar range. This method will be useful in the discovery of RNA aptamers and ribozymes containing base modifications that make them resistant to accurate reverse transcription.
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Affiliation(s)
- I S MacPherson
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawai'i at Manoa, 651 Ilalo St., Biosciences Building, Suite 325, Honolulu, Hawaii 96813-5525, USA. and Department of Chemistry, Brandeis University, 415 South St. MS 015, Waltham, MA 02454-9110, USA.
| | - J S Temme
- Department of Chemistry, Brandeis University, 415 South St. MS 015, Waltham, MA 02454-9110, USA.
| | - I J Krauss
- Department of Chemistry, Brandeis University, 415 South St. MS 015, Waltham, MA 02454-9110, USA.
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Minagawa H, Onodera K, Fujita H, Sakamoto T, Akitomi J, Kaneko N, Shiratori I, Kuwahara M, Horii K, Waga I. Selection, Characterization and Application of Artificial DNA Aptamer Containing Appended Bases with Sub-nanomolar Affinity for a Salivary Biomarker. Sci Rep 2017; 7:42716. [PMID: 28256555 PMCID: PMC5335659 DOI: 10.1038/srep42716] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/12/2017] [Indexed: 12/21/2022] Open
Abstract
We have attained a chemically modified DNA aptamer against salivary α-amylase (sAA), which attracts researchers’ attention as a useful biomarker for assessing human psychobiological and social behavioural processes, although high affinity aptamers have not been isolated from a random natural DNA library to date. For the selection, we used the base-appended base (BAB) modification, that is, a modified-base DNA library containing (E)-5-(2-(N-(2-(N6-adeninyl)ethyl))carbamylvinyl)-uracil in place of thymine. After eight rounds of selection, a 75 mer aptamer, AMYm1, which binds to sAA with extremely high affinity (Kd < 1 nM), was isolated. Furthermore, we have successfully determined the 36-mer minimum fragment, AMYm1-3, which retains target binding activity comparable to the full-length AMYm1, by surface plasmon resonance assays. Nuclear magnetic resonance spectral analysis indicated that the minimum fragment forms a specific stable conformation, whereas the predicted secondary structures were suggested to be disordered forms. Thus, DNA libraries with BAB-modifications can achieve more diverse conformations for fitness to various targets compared with natural DNA libraries, which is an important advantage for aptamer development. Furthermore, using AMYm1, a capillary gel electrophoresis assay and lateral flow assay with human saliva were conducted, and its feasibility was demonstrated.
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Affiliation(s)
- Hirotaka Minagawa
- Innovation Laboratory, NEC Solution Innovators, Ltd., 1-18-7, Shinkiba, Koto-Ku, Tokyo 136-8627, Japan
| | - Kentaro Onodera
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Hiroto Fujita
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Taiichi Sakamoto
- Department of Life and Environmental Sciences, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino 275-0016, Japan
| | - Joe Akitomi
- Innovation Laboratory, NEC Solution Innovators, Ltd., 1-18-7, Shinkiba, Koto-Ku, Tokyo 136-8627, Japan
| | - Naoto Kaneko
- Innovation Laboratory, NEC Solution Innovators, Ltd., 1-18-7, Shinkiba, Koto-Ku, Tokyo 136-8627, Japan
| | - Ikuo Shiratori
- Innovation Laboratory, NEC Solution Innovators, Ltd., 1-18-7, Shinkiba, Koto-Ku, Tokyo 136-8627, Japan
| | - Masayasu Kuwahara
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Katsunori Horii
- Innovation Laboratory, NEC Solution Innovators, Ltd., 1-18-7, Shinkiba, Koto-Ku, Tokyo 136-8627, Japan
| | - Iwao Waga
- Innovation Laboratory, NEC Solution Innovators, Ltd., 1-18-7, Shinkiba, Koto-Ku, Tokyo 136-8627, Japan
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Generation of Aptamers with an Expanded Chemical Repertoire. Molecules 2015; 20:16643-71. [PMID: 26389865 PMCID: PMC6332006 DOI: 10.3390/molecules200916643] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 08/28/2015] [Accepted: 09/01/2015] [Indexed: 01/03/2023] Open
Abstract
The enzymatic co-polymerization of modified nucleoside triphosphates (dN*TPs and N*TPs) is a versatile method for the expansion and exploration of expanded chemical space in SELEX and related combinatorial methods of in vitro selection. This strategy can be exploited to generate aptamers with improved or hitherto unknown properties. In this review, we discuss the nature of the functionalities appended to nucleoside triphosphates and their impact on selection experiments. The properties of the resulting modified aptamers will be described, particularly those integrated in the fields of biomolecular diagnostics, therapeutics, and in the expansion of genetic systems (XNAs).
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21
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Abstract
To expand the chemical functionality of DNAzymes and aptamers, several new modified deoxyuridine triphosphates have been synthesized. An important precursor that enables this aim is 5-aminomethyl dUTP, whereby the pendent amine serves as a handle for further synthetic functionalization. Five functional groups were conjugated to 5-aminomethyl dUTP. Incorporation assays were performed on several templates that demand 2-5 sequential incorporation events using several commercially available DNA polymerases. It was found that Vent (exo-) DNA polymerase efficiently incorporates all five modified dUTPs. In addition, all nucleoside triphosphates were capable of supporting a double-stranded exponential PCR amplification. Modified PCR amplicons were PCR amplified into unmodified DNA and sequenced to verify that genetic information was conserved through incorporation, amplification, and reamplification. Overall these modified dUTPs represent new candidate substrates for use in selections using modified nucleotide libraries.
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Nucleic Acid Ligands With Protein-like Side Chains: Modified Aptamers and Their Use as Diagnostic and Therapeutic Agents. MOLECULAR THERAPY-NUCLEIC ACIDS 2014; 3:e201. [PMID: 25291143 PMCID: PMC4217074 DOI: 10.1038/mtna.2014.49] [Citation(s) in RCA: 347] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/12/2014] [Indexed: 12/30/2022]
Abstract
Limited chemical diversity of nucleic acid libraries has long been suspected to be a major constraining factor in the overall success of SELEX (Systematic Evolution of Ligands by EXponential enrichment). Despite this constraint, SELEX has enjoyed considerable success over the past quarter of a century as a result of the enormous size of starting libraries and conformational richness of nucleic acids. With judicious introduction of functional groups absent in natural nucleic acids, the “diversity gap” between nucleic acid–based ligands and protein-based ligands can be substantially bridged, to generate a new class of ligands that represent the best of both worlds. We have explored the effect of various functional groups at the 5-position of uracil and found that hydrophobic aromatic side chains have the most profound influence on the success rate of SELEX and allow the identification of ligands with very low dissociation rate constants (named Slow Off-rate Modified Aptamers or SOMAmers). Such modified nucleotides create unique intramolecular motifs and make direct contacts with proteins. Importantly, SOMAmers engage their protein targets with surfaces that have significantly more hydrophobic character compared with conventional aptamers, thereby increasing the range of epitopes that are available for binding. These improvements have enabled us to build a collection of SOMAmers to over 3,000 human proteins encompassing major families such as growth factors, cytokines, enzymes, hormones, and receptors, with additional SOMAmers aimed at pathogen and rodent proteins. Such a large and growing collection of exquisite affinity reagents expands the scope of possible applications in diagnostics and therapeutics.
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23
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Yao J, Yang M, Duan Y. Chemistry, Biology, and Medicine of Fluorescent Nanomaterials and Related Systems: New Insights into Biosensing, Bioimaging, Genomics, Diagnostics, and Therapy. Chem Rev 2014; 114:6130-78. [DOI: 10.1021/cr200359p] [Citation(s) in RCA: 592] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jun Yao
- Research
Center of Analytical Instrumentation, Analytical and Testing Center,
College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Mei Yang
- Research
Center of Analytical Instrumentation, Analytical and Testing Center,
College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Yixiang Duan
- Research
Center of Analytical Instrumentation, Analytical and Testing Center,
College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
- Research
Center of Analytical Instrumentation, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
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Kuwahara M, Obika S. In vitro selection of BNA (LNA) aptamers. ARTIFICIAL DNA, PNA & XNA 2014; 4:39-48. [PMID: 24044051 DOI: 10.4161/adna.25786] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/17/2013] [Indexed: 01/03/2023]
Abstract
Recently, we achieved the first in vitro selection of 2'-O,4'-C-methylene bridged/locked nucleic acid (2',4'-BNA/LNA) aptamers. High-affinity thrombin-binding aptamers (TBAs) were obtained from DNA-based libraries containing 2'-O,4'-C-methylene-bridged/linked bicyclic ribonucleotides (B/L nucleotides) in the 5'-primer region, using the method of capillary electrophoresis systematic evolution of ligands by exponential enrichment (CE-SELEX). Furthermore, a similar selection protocol could provide TBAs that contain B/L nucleotides in both primer and random regions. We review technical challenges involved in the generation of various BNA libraries using analogs of B/L nucleoside-5'-triphosphate and polymerase variants and also discuss applications of these libraries to the selection of BNA (LNA) aptamers, as well as future prospects for their therapeutic and diagnostic uses.
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Affiliation(s)
- Masayasu Kuwahara
- Graduate School of Science and Technology; Gunma University; Gunma, Japan
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25
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Imaizumi Y, Kasahara Y, Fujita H, Kitadume S, Ozaki H, Endoh T, Kuwahara M, Sugimoto N. Efficacy of base-modification on target binding of small molecule DNA aptamers. J Am Chem Soc 2013; 135:9412-9. [PMID: 23734784 DOI: 10.1021/ja4012222] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nucleic acid aptamers are receptors of single-stranded oligonucleotides that specifically bind to their targets. Significant interest is currently focused on development of small molecule aptamers owing to their applications in biosensing, diagnostics, and therapeutics involving low molecular weight biomarkers and drugs. Despite great potential for their diverse applications, relatively few aptamers that bind to small molecules have been reported, and methodologies to enhance and broaden their functions by expanding chemical repertories have barely been examined. Here we describe construction of a modified DNA library that includes (E)-5-(2-(N-(2-(N(6)-adeninyl)ethyl))carbamylvinyl)-uracil bases and discovery of high-affinity camptothecin-binding DNA aptamers using a systematic evolution of ligands by the exponential enrichment method. Our results are the first to demonstrate the superior efficacy of base modification on affinity enhancement and the usefulness of unnatural nucleic acid libraries for development of small molecule aptamers.
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Affiliation(s)
- Yuri Imaizumi
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
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26
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Hollenstein M, Hipolito CJ, Lam CH, Perrin DM. Toward the combinatorial selection of chemically modified DNAzyme RNase A mimics active against all-RNA substrates. ACS COMBINATORIAL SCIENCE 2013; 15:174-82. [PMID: 23485334 DOI: 10.1021/co3001378] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The convenient use of SELEX and related combinatorial methods of in vitro selection provides a formidable gateway for the generation of DNA enzymes, especially in the context of improving their potential as gene therapeutic agents. Here, we report on the selection of DNAzyme 12-91, a modified nucleic acid catalyst adorned with imidazole, ammonium, and guanidinium groups that provide for efficient M(2+)-independent cleavage of an all-RNA target sequence (kobs = 0.06 min(-1)). While Dz12-91 was selected for intramolecular cleavage of an all-RNA target, it surprisingly cleaves a target containing a lone ribocytosine unit with even greater efficiency (kobs = 0.27 min(-1)) than Dz9-86 (kobs = 0.13 min(-1)). The sequence composition of Dz12-91 bears a marked resemblance to that of Dz9-86 (kobs = 0.0014 min(-1) with an all-RNA substrate) that was selected from the same library to cleave a target containing a single ribonucleotide. However, small alterations in the sequence composition have a profound impact on the substrate preference and catalytic properties. Indeed, Dz12-91 displays the highest known rate enhancement for the M(2+)-independent cleavage of all-RNA targets. Hence, Dz12-91 represents a step toward the generation of potentially therapeutically active DNAzymes and further underscores the usefulness of modified triphosphates in selection experiments.
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Affiliation(s)
- Marcel Hollenstein
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC, V6T
1Z1, Canada
| | - Christopher J. Hipolito
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC, V6T
1Z1, Canada
| | - Curtis H. Lam
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC, V6T
1Z1, Canada
| | - David M. Perrin
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC, V6T
1Z1, Canada
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27
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Manoli K, Magliulo M, Torsi L. Chiral Sensor Devices for Differentiation of Enantiomers. Top Curr Chem (Cham) 2013; 341:133-76. [DOI: 10.1007/128_2013_444] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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28
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Challenges and opportunities for small molecule aptamer development. J Nucleic Acids 2012; 2012:748913. [PMID: 23150810 PMCID: PMC3488411 DOI: 10.1155/2012/748913] [Citation(s) in RCA: 286] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 09/08/2012] [Indexed: 12/14/2022] Open
Abstract
Aptamers are single-stranded oligonucleotides that bind to targets with high affinity and selectivity. Their use as molecular recognition elements has emerged as a viable approach for biosensing, diagnostics, and therapeutics. Despite this potential, relatively few aptamers exist that bind to small molecules. Small molecules are important targets for investigation due to their diverse biological functions as well as their clinical and commercial uses. Novel, effective molecular recognition probes for these compounds are therefore of great interest. This paper will highlight the technical challenges of aptamer development for small molecule targets, as well as the opportunities that exist for their application in biosensing and chemical biology.
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29
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Abstract
Aptamers are single-stranded oligonucleotides that bind to targets with high affinity and selectivity. Their use as molecular recognition elements has emerged as a viable approach for biosensing, diagnostics, and therapeutics. Despite this potential, relatively few aptamers exist that bind to small molecules. Small molecules are important targets for investigation due to their diverse biological functions as well as their clinical and commercial uses. Novel, effective molecular recognition probes for these compounds are therefore of great interest. This paper will highlight the technical challenges of aptamer development for small molecule targets, as well as the opportunities that exist for their application in biosensing and chemical biology.
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30
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Kasahara Y, Kuwahara M. Artificial specific binders directly recovered from chemically modified nucleic acid libraries. J Nucleic Acids 2012; 2012:156482. [PMID: 23094139 PMCID: PMC3472525 DOI: 10.1155/2012/156482] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 08/19/2012] [Indexed: 11/18/2022] Open
Abstract
Specific binders comprised of nucleic acids, that is, RNA/DNA aptamers, are attractive functional biopolymers owing to their potential broad application in medicine, food hygiene, environmental analysis, and biological research. Despite the large number of reports on selection of natural DNA/RNA aptamers, there are not many examples of direct screening of chemically modified nucleic acid aptamers. This is because of (i) the inferior efficiency and accuracy of polymerase reactions involving transcription/reverse-transcription of modified nucleotides compared with those of natural nucleotides, (ii) technical difficulties and additional time and effort required when using modified nucleic acid libraries, and (iii) ambiguous efficacies of chemical modifications in binding properties until recently; in contrast, the effects of chemical modifications on biostability are well studied using various nucleotide analogs. Although reports on the direct screening of a modified nucleic acid library remain in the minority, chemical modifications would be essential when further functional expansion of nucleic acid aptamers, in particular for medical and biological uses, is considered. This paper focuses on enzymatic production of chemically modified nucleic acids and their application to random screenings. In addition, recent advances and possible future research are also described.
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Affiliation(s)
- Yuuya Kasahara
- Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan
| | - Masayasu Kuwahara
- Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan
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Selecting Molecular Recognition. What Can Existing Aptamers Tell Us about Their Inherent Recognition Capabilities and Modes of Interaction? Pharmaceuticals (Basel) 2012; 5:493-513. [PMID: 24281560 PMCID: PMC3763653 DOI: 10.3390/ph5050493] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/19/2012] [Accepted: 05/10/2012] [Indexed: 01/02/2023] Open
Abstract
The use of nucleic acid derived aptamers has rapidly expanded since the introduction of SELEX in 1990. Nucleic acid aptamers have demonstrated their ability to target a broad range of molecules in ways that rival antibodies, but advances have been very uneven for different biochemical classes of targets, and clinical applications have been slow to emerge. What sets different aptamers apart from each other and from rivaling molecular recognition platforms, specifically proteins? What advantages do aptamers as a reagent class offer, and how do the chemical properties and selection procedures of aptamers influence their function? Do the building blocks of nucleic acid aptamers dictate inherent limitations in the nature of molecular targets, and do existing aptamers give us insight in how these challenges might be overcome? This review is written as an introduction for potential endusers of aptamer technology who are evaluating the advantages of aptamers as a versatile, affordable, yet highly expandable platform to target a broad range of biological processes or interactions.
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Kashefi-Kheyrabadi L, Mehrgardi MA. Design and construction of a label free aptasensor for electrochemical detection of sodium diclofenac. Biosens Bioelectron 2012; 33:184-9. [PMID: 22265876 DOI: 10.1016/j.bios.2011.12.050] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/05/2011] [Accepted: 12/25/2011] [Indexed: 10/14/2022]
Abstract
The present manuscript describes a label free electrochemical aptasensor for the detection of sodium diclofenac (DCF). In order to construct the biosensor, the amino-functionalized diclofenac binding aptamer (DBA) was covalently immobilized on the surface of the glassy carbon electrode (GCE). The conformation of the DBAs on the surface of the electrode is changed when this is exposed to different concentrations of DCF. The introduction of DCF induces an alteration in the conformation of the surface immobilized DBA and causes a decrease in the charge transfer resistance of the aptasensor. However, the charge transfer resistance is increased by incubation of GCE/DBA/DCF in the secondary DBA. The changes in the charge transfer resistance have been monitored using the voltammetric and electrochemical impedance spectroscopic (EIS) techniques. The aptasensor shows two different linear dynamic ranges over 0-5.0 μM and 10 μM to 1mM, and the sensitivity of 15.7 kΩ μM(-1) and detection limit of 2.7 × 10(-7)M were obtained. The validity of the method and applicability of the aptasensor were successfully evaluated by detection of DCF in a blood serum sample without interference from the sample matrix. Furthermore, the aptasensor has shown good stability.
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33
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Hua M, Tao M, Wang P, Zhang Y, Wu Z, Chang Y, Yang Y. Label-free electrochemical cocaine aptasensor based on a target-inducing aptamer switching conformation. ANAL SCI 2011; 26:1265-70. [PMID: 21157095 DOI: 10.2116/analsci.26.1265] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A novel label-free electrochemical nucleic acid aptasensor for the determination of cocaine by the immobilization of thiolated self-assembled DNA sequences on a gold nanoparticles-modified electrode is presented. When cocaine was complexed specifically to the aptamer, the configuration of the nucleic acid aptamer switched to a locked structure and the interface of the biosensor changed, resulting in a variation of the corresponding peak current of an electrochemical probe ([Fe(CN)(6)](3-/4-)). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to characterize modifications of the electrode surface. The peak current was detected by differential pulse voltammetry (DPV). Under the optimized experimental conditions, the presented sensor exhibits a nice specificity towards cocaine. The decrease of the peak current response of the aptasensor has a linear relationship with the concentration of cocaine ranging from 1.0 × 10(-6) to 1.5 × 10(-4) mol L(-1) with a detection limit of 3 × 10(-7) mol L(-1) at 3σ. The proposed aptasensor can be easily regenerated by the denaturalization of aptamer-target complexes in a heated water bath at 80-90°C. Besides, this biosensor has a high reproducibility and selectivity, which can be a promising method to detect cocaine in real samples.
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Affiliation(s)
- Mei Hua
- College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming, P. R. China
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34
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Hipolito CJ, Hollenstein M, Lam CH, Perrin DM. Protein-inspired modified DNAzymes: dramatic effects of shortening side-chain length of 8-imidazolyl modified deoxyadenosines in selecting RNaseA mimicking DNAzymes. Org Biomol Chem 2011; 9:2266-73. [PMID: 21311779 DOI: 10.1039/c0ob00595a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The discovery of imidazole/amine-functionalized DNAzymes that efficiently cleave RNA independently of divalent metal cations (M(2+)) and cofactors underscores the importance of expanding the catalytic repertoire with modified nucleosides. Considerable effort has gone into defining polymerase tolerances of various modified dNTPs for synthesizing and amplifying modified DNA. While long linkers are generally found to enhance incorporation and therefore increase sequence space, shorter linkers may reduce the entropic penalty paid for orienting catalytic functionality. Catalytic enhancement ultimately depends on both the functional group and appropriate linkage to the nucleobase. Whether a shorter linker provides enough catalytic enhancement to outweigh the cost of reduced polymerizability can only be determined by the outcome of the selection. Herein, we report the selection of DNAzyme 20-49 (Dz20-49), which depends on amine, guanidine, and imidazole-modified dNTPs. In contrast to previous selections where we used dA(ime)TP (8-(4-imidazolyl)ethylamino-2'-dATP), here we used dA(imm)TP (8-(4-imidazolyl)methylamino-2'-dATP), in which the linker arm is shortened by one methylene group. Although the most active clone, Dz20-49, was absolutely dependent on the incorporation of either dA(imm)p or dA(ime)p, it catalyzed cofactor independent self-cleavage with a rate constant of 3.1 ± 0.3 × 10(-3) min(-1), a value not dissimilar from unmodified catalysts and strikingly inferior to modified catalysts selected with dA(ime)TP. These results demonstrate that very subtle differences in modified nucleotide composition may dramatically effect DNAzyme selection.
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Affiliation(s)
- Christopher J Hipolito
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada
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Introduction of guanidinium-modified deoxyuridine into the substrate binding regions of DNAzyme 10–23 to enhance target affinity: Implications for DNAzyme design. Bioorg Med Chem Lett 2010; 20:5119-22. [DOI: 10.1016/j.bmcl.2010.07.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 07/04/2010] [Accepted: 07/07/2010] [Indexed: 12/22/2022]
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Rich RL, Myszka DG. Grading the commercial optical biosensor literature-Class of 2008: 'The Mighty Binders'. J Mol Recognit 2010; 23:1-64. [PMID: 20017116 DOI: 10.1002/jmr.1004] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Optical biosensor technology continues to be the method of choice for label-free, real-time interaction analysis. But when it comes to improving the quality of the biosensor literature, education should be fundamental. Of the 1413 articles published in 2008, less than 30% would pass the requirements for high-school chemistry. To teach by example, we spotlight 10 papers that illustrate how to implement the technology properly. Then we grade every paper published in 2008 on a scale from A to F and outline what features make a biosensor article fabulous, middling or abysmal. To help improve the quality of published data, we focus on a few experimental, analysis and presentation mistakes that are alarmingly common. With the literature as a guide, we want to ensure that no user is left behind.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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A DNAzyme with Three Protein-Like Functional Groups: Enhancing Catalytic Efficiency of M2+-Independent RNA Cleavage. Chembiochem 2009; 10:1988-92. [DOI: 10.1002/cbic.200900314] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Kuwahara M, Takeshima H, Nagashima JI, Minezaki S, Ozaki H, Sawai H. Transcription and reverse transcription of artificial nucleic acids involving backbone modification by template-directed DNA polymerase reactions. Bioorg Med Chem 2009; 17:3782-8. [PMID: 19427792 DOI: 10.1016/j.bmc.2009.04.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 04/21/2009] [Accepted: 04/22/2009] [Indexed: 12/22/2022]
Abstract
Oligodeoxyribonucleotides (ODN) where the phosphodiester linkage had been replaced with an amide-type linker [-CH(2)C=ONH-] or an amine-type linker [-CH(2)CH(2)NH-] were synthesized to investigate the effect of these backbone modifications on polymerase reactions. In addition, a triphosphate analogue of thymidine dinucleotide with the amide-type linker was synthesized and enzymatic insertion of the amide linkage into ODN was attempted using this analogue for the polymerase reaction. Primer extension reactions using three types of thermostable DNA polymerases, KOD(exo-), Vent(exo-) and Taq were performed for the assays. Analysis of these data indicate that (i) the polymerase reaction tends to be affected much more by insertion of the cationic flexible amine-type linker than by insertion of the neutral rigid amide-type linker; (ii) the backbone modification has a greater effect on the polymerase reaction when it is adjacent to the 3'-end of a primer as the elongation terminus than when it is on the template, as well as in base or sugar modification; (iii) although the modified linker in the modified DNA template is passed beyond by the polymerase, it still affects the extension reaction several bases downstream from its location; (iv) the modified linker in the template, in some cases, also affects the extension reaction upstream from its location; (v) further improvement of the chemical structure is required for dinucleotide-mimic incorporation.
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Affiliation(s)
- Masayasu Kuwahara
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Gunma 376-8515, Japan.
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Hollenstein M, Hipolito CJ, Lam CH, Perrin DM. A self-cleaving DNA enzyme modified with amines, guanidines and imidazoles operates independently of divalent metal cations (M2+). Nucleic Acids Res 2009; 37:1638-49. [PMID: 19153138 PMCID: PMC2655665 DOI: 10.1093/nar/gkn1070] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 12/18/2008] [Accepted: 12/19/2008] [Indexed: 12/04/2022] Open
Abstract
The selection of modified DNAzymes represents an important endeavor in expanding the chemical and catalytic properties of catalytic nucleic acids. Few examples of such exist and to date, there is no example where three different modified bases have been simultaneously incorporated for catalytic activity. Herein, dCTP, dATP and dUTP bearing, respectively, a cationic amine, an imidazole and a cationic guanidine, were enzymatically polymerized on a DNA template for the selection of a highly functionalized DNAzyme, called DNAzyme 9-86, that catalyzed (M(2+))-independent self-cleavage under physiological conditions at a single ribo(cytosine)phosphodiester linkage with a rate constant of (0.134 +/- 0.026) min(-1). A pH rate profile analysis revealed pK(a)'s of 7.4 and 8.1, consistent with both general acid and base catalysis. The presence of guanidinium cations permits cleavage at significantly higher temperatures than previously observed for DNAzymes with only amines and imidazoles. Qualitatively, DNAzyme 9-86 presents an unprecedented ensemble of synthetic functionalities while quantitatively it expresses one of the highest reported values for any self-cleaving nucleic acid when investigated under M(2+)-free conditions at 37 degrees C.
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Affiliation(s)
| | | | | | - David M. Perrin
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC, V6T 1Z1, Canada
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Du Y, Li B, Wang F, Dong S. Au nanoparticles grafted sandwich platform used amplified small molecule electrochemical aptasensor. Biosens Bioelectron 2008; 24:1979-83. [PMID: 19101135 DOI: 10.1016/j.bios.2008.10.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 10/04/2008] [Accepted: 10/06/2008] [Indexed: 10/21/2022]
Abstract
We report a sensitively amplified electrochemical aptasensor using adenosine triphosphate (ATP) as a model. ATP is a multifunctional nucleotide that is most important as a "molecular currency" of intracellular energy transfer. In the sensing process, duplexes consisting of partly complementary strand (PCS1), ATP aptamer (ABA) and another partly complementary strand (PCS2) were immobilized onto Au electrode through the 5'-HS on the PCS1. Meanwhile, PCS2 was grafted with the Au nanoparticles (AuNPs) to amplify the detection signals. In the absence of ATP, probe methylene blue (MB) bound to the DNA duplexes and also bound to guanine bases specifically to produce a strong differential pulse voltammetry (DPV) signal. But when ATP exists, the ABA-PCS2 or ABA-PCS1 part duplexes might be destroyed, which decreased the amount of MB on the electrode and led to obviously decreased DPV signal. This phenomenon can be used to detect ATP and get a very sensitive detection limit low to 0.1nM, and the detection range could extend up to 10(-7)M. Compared to the sensing platform without PCS2 grafted AuNPs, amplified function of this sensing system was also evidently proved. Therefore, such PCS1-ABA-PCS2/AuNPs sensing system could provide a promising signal-amplified model for aptamer-based small-molecules detection.
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Affiliation(s)
- Yan Du
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China
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Debbage P, Jaschke W. Molecular imaging with nanoparticles: giant roles for dwarf actors. Histochem Cell Biol 2008; 130:845-75. [PMID: 18825403 DOI: 10.1007/s00418-008-0511-y] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2008] [Indexed: 10/25/2022]
Abstract
Molecular imaging, first developed to localise antigens in light microscopy, now encompasses all imaging modalities including those used in clinical care: optical imaging, nuclear medical imaging, ultrasound imaging, CT, MRI, and photoacoustic imaging. Molecular imaging always requires accumulation of contrast agent in the target site, often achieved most efficiently by steering nanoparticles containing contrast agent into the target. This entails accessing target molecules hidden behind tissue barriers, necessitating the use of targeting groups. For imaging modalities with low sensitivity, nanoparticles bearing multiple contrast groups provide signal amplification. The same nanoparticles can in principle deliver both contrast medium and drug, allowing monitoring of biodistribution and therapeutic activity simultaneously (theranostics). Nanoparticles with multiple bioadhesive sites for target recognition and binding will be larger than 20 nm diameter. They share functionalities with many subcellular organelles (ribosomes, proteasomes, ion channels, and transport vesicles) and are of similar sizes. The materials used to synthesise nanoparticles include natural proteins and polymers, artificial polymers, dendrimers, fullerenes and other carbon-based structures, lipid-water micelles, viral capsids, metals, metal oxides, and ceramics. Signal generators incorporated into nanoparticles include iron oxide, gadolinium, fluorine, iodine, bismuth, radionuclides, quantum dots, and metal nanoclusters. Diagnostic imaging applications, now appearing, include sentinal node localisation and stem cell tracking.
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Affiliation(s)
- Paul Debbage
- Department of Anatomy, Division of Histology and Embryology, Medical University Innsbruck, Muellerstrasse 59, 6020, Innsbruck, Austria.
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Kuwahara M, Obika S, Nagashima JI, Ohta Y, Suto Y, Ozaki H, Sawai H, Imanishi T. Systematic analysis of enzymatic DNA polymerization using oligo-DNA templates and triphosphate analogs involving 2',4'-bridged nucleosides. Nucleic Acids Res 2008; 36:4257-65. [PMID: 18583360 PMCID: PMC2490744 DOI: 10.1093/nar/gkn404] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 06/07/2008] [Accepted: 06/09/2008] [Indexed: 11/16/2022] Open
Abstract
In order to systematically analyze the effects of nucleoside modification of sugar moieties in DNA polymerase reactions, we synthesized 16 modified templates containing 2',4'-bridged nucleotides and three types of 2',4'-bridged nucleoside-5'-triphospates with different bridging structures. Among the five types of thermostable DNA polymerases used, Taq, Phusion HF, Vent(exo-), KOD Dash and KOD(exo-), the KOD Dash and KOD(exo-) DNA polymerases could smoothly read through the modified templates containing 2'-O,4'-C-methylene-linked nucleotides at intervals of a few nucleotides, even at standard enzyme concentrations for 5 min. Although the Vent(exo-) DNA polymerase also read through these modified templates, kinetic study indicates that the KOD(exo-) DNA polymerase was found to be far superior to the Vent(exo-) DNA polymerase in accurate incorporation of nucleotides. When either of the DNA polymerase was used, the presence of 2',4'-bridged nucleotides on a template strand substantially decreased the reaction rates of nucleotide incorporations. The modified templates containing sequences of seven successive 2',4'-bridged nucleotides could not be completely transcribed by any of the DNA polymerases used; yields of longer elongated products decreased in the order of steric bulkiness of the modified sugars. Successive incorporation of 2',4'-bridged nucleotides into extending strands using 2',4'-bridged nucleoside-5'-triphospates was much more difficult. These data indicate that the sugar modification would have a greater effect on the polymerase reaction when it is adjacent to the elongation terminus than when it is on the template as well, as in base modification.
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Affiliation(s)
- Masayasu Kuwahara
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Gunma 376-8515, Japan.
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